The provision of efficient, cost-effective and durable means for storing electrical energy is one of the key technologies that are of importance for the change-over of motor vehicles to electric drives as well as for the development of regenerative sources of energy. Nowadays, batteries, accumulators or capacitors are used as a means for storing electrical energy. Especially accumulators, preferably lithium ion accumulators, have high energy densities and therefore allow an efficient storage of electrical energy. The current collector foils of the cathode of a lithium ion accumulator may be made from an aluminium foil, which provides very good electrical conductivity at low material costs. The current collector foil of the cathode is here additionally coated with a metal oxide, for example with a lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate or with other active electrode materials. The metal oxide forms the active electrode material that can receive lithium ions during the discharge process and can, during the charging process, release these again to an anode, the active electrode material of which is graphite, for example. It has been found that the size of the contact surface and the adhesion between the active electrode material and the current collector foil are factors that have an effect on the service life of the lithium ion accumulator as well as on the capacity retention thereof. The adhesion between the current collector foil and the active electrode material as well as the contact surface of the current collector foil with the active electrode material are critical factors for achieving constant charging and discharging properties of the lithium ion accumulator. If the active electrode material becomes partially separated, the capacity will decrease down to a complete failure of the accumulator. Moreover, in order to produce maximum capacity it is desirable to maximise the contact surface between the current collector foil and the active electrode material. The same principally also applies to other types of accumulators, batteries and capacitors that have current collector foils and are of a similar design.
Furthermore, a method for electrochemically depositing metals, in particular aluminium, from ionic liquids is known from published German document DE 101 08 893 A1.